1. Field of Invention
The present invention relates to an endoscopic surgical cutting stapler used in endoscopic surgeries, specifically to an endoscopic surgical cutting stapler used in laparoscopic surgeries and an endoscopic surgical cutting stapler used in thoracoscopic surgeries, and more specifically to an endoscopic surgical cutting stapler with a chain articulation.
2. Description of Related Arts
In laparoscopic surgeries and thoracoscopic surgeries, an endoscopic surgical cutting stapler is usually used in cutting and stapling surgeries on esophagus, stomach, duodenum, small intestine, colon, rectum, vermiform appendix, gallbladder, pancreas, and spleen in the digestive tract, in cutting and stapling surgeries on lung and trachea in the respiratory tract, and also in cutting and stapling surgeries on bladder and uterus in the genitourinary system, so as to shorten the surgery period and improve the surgery quality.
US Patent Publication No. US20080308602, No. US20090206124, and No. US20090206137 disclose various endoscopic surgical cutting staplers in the prior art. When an endoscopic surgical cutting stapler is used, an end effector first enters a body cavity through a puncture needle with an inner diameter of 12 mm to 13 mm. Then the end effector is controlled to perform axial rotation and joint rotation, so as to be aligned with tissue to be cut and stapled. At this time, a clamping mechanism can be operated, and a slide bar is pushed, to clamp the tissue to be cut and stapled between a staple anvil and a staple cartridge of the end effector. An actuation mechanism is then operated, and the slide bar is further pushed. Two ends of the slide bar are respectively inserted into the staple anvil and staple cartridge of the end effector, so that a required clamping thickness is achieved between the staple anvil and staple cartridge. The slide bar pushes the staple pushing block through a staple pushing sled, to eject the staple from the staple cartridge through the clamped tissue to be cut and stapled and against a staple forming slot on the staple anvil, so that the U-shaped staple is deformed into a B-shaped staple, thereby stapling the tissue. A cutter blade on the slide bar cuts the clamped tissue to be cut and stapled, so as to achieve the surgery purpose of cutting the tissue. After the cutting and stapling operations, the clamping mechanism is operated to loosen the cut and stapled tissue, so that the tissue exits the endoscopic surgical cutting stapler. Other operating mechanisms may also be used as the clamping mechanism and the actuation mechanism of the endoscopic surgical cutting stapler. The operating mechanism may further include an indicating mechanism. Operating mechanisms such as the clamping mechanism and the actuation mechanism of the endoscopic surgical cutting stapler may be manual endoscopic surgical cutting staplers disclosed in US Patent Publication No. US20080308602 and No. US20090206137, electric endoscopic surgical cutting staplers disclosed in US Patent Publication No. US20090090763 and No. US20090095790, or fluid-driven endoscopic surgical cutting stapler disclosed in US Patent Publication No. US20070125826 and No. US20080029577.
An existing endoscopic surgical cutting stapler includes an end effector, an articulation, an extension tube, a stapler body, and an operating mechanism. The operating mechanism is located on the stapler body, and is used to control an action of the end effector. The end effector, the articulation, the extension tube, and the stapler body are connected in sequence. The end effector consists of a support, a slide bar, a staple cartridge, and a staple anvil. The slide bar, the staple cartridge, and the staple anvil are mounted on the support. The staple cartridge consists of a staple cartridge housing, staple pushing blocks, a staple pushing sled, and staples. Staple slots, staple pushing holes, sled slots, and a blade pushing slot are provided in the staple cartridge housing. The staples are mounted in the staple slots. The staple pushing blocks are mounted in the staple pushing holes. The staple pushing sled is mounted in the blade pushing slot and the sled slot. The staple slots and the staple pushing holes of the staple cartridge housing are aligned in rows at two sides of the blade pushing slot. The staple pushing block is movable in the staple pushing hole to force the staple out of the staple slot. The staple pushing sled pushes the staple pushing block to move in the staple pushing hole through a slope, thereby forcing the staple out of the staple slot. The staple is U-shaped and consists of two staple legs, a staple beam, and two staple tips. One end of each staple leg is connected to the staple beam, and the other end is the staple tip. The staple may be made of stainless steel wires, tantalum wires, titanium wires, or other metal wires having similar properties. Two staple legs are inserted in the staple slot. The staple beam is seated at an upper edge of the staple pushing block. An end surface of the staple anvil is provided with staple forming slots corresponding to positions of the staples in the staple cartridge, and is also provided with a cutting slot corresponding to a position of the blade pushing slot in the staple cartridge housing. The staple forming slots of the staple anvil are correspondingly aligned in rows at two sides of the cutting slot of the staple anvil. The staple slots and staple pushing holes of the staple cartridge, and the staple forming slots of the staple anvil may be aligned in two rows, three rows, four rows, five rows, six rows, seven rows, or eight rows according to the cutting and stapling requirements of surgeries. The staple anvil may be pivoted to the support. The slide bar is movable in the blade pushing slot of the staple cartridge and the cutting slot of the staple anvil. When the staple anvil pivotally rotates around the support, the staple anvil and the staple cartridge clamp or loosen the tissue to be cut and stapled. When a required gap is achieved between the staple anvil and the staple cartridge, a required clamping thickness of the tissue to be cut and stapled is achieved between the staple anvil and the staple cartridge.
When the endoscopic surgical cutting stapler is used, an end effector first enters a body cavity through a puncture needle with an inner diameter of 12 mm to 13 mm. Then the end effector is controlled to perform axial rotation and joint rotation, so as to be aligned with the tissue to be cut and stapled. If the end effector fails to be aligned with the tissue to be cut and stapled, the end effector cannot clamp the tissue to be cut and stapled between the staple anvil and staple cartridge, and cannot perform cutting and stapling operations. In endoscopic surgical cutting staplers disclosed in US Patent Publication No. US20090206131 and No. 20100163597, the end effector and the extension tube are jointed through a pivot pin. The slide bar is formed by stacked thin plates. The end effector is pulled by a pull rod extending from the extension tube and sleeved on the end effector, thereby controlling the end effector to perform joint rotation around the pivot pin and relative to the extension tube. The thin plates of the slide bar rotate toward two sides along with the articulation and are bended toward the two sides. Such endoscopic surgical cutting stapler has the following disadvantage: restricted by the pivot pin, the end effector can only perform joint rotation around the pivot pin and relative to the extension tube; when a bending angle of the slide bar is small, the slide bar bended in an internal space of the articulation has a large radius of curvature; however, when the bending angle of the slide bar is large, restricted by the internal space of the articulation, the slide bar bended around the pivot pin in the internal space of the articulation has a small radius of curvature. Although it is stated in US Patent Publication No. US20090206131 and No. US20100163597 that the endoscopic surgical cutting stapler can have a joint rotation angle up to 90°, restricted by the bending deformation of the slide bar material, an actual joint rotation angle of the product is no more than 40°. The endoscopic surgical cutting stapler is restricted by an inner bore of the puncture needle. Therefore, when the pivot joint rotation angle of the end effector is no more than 40°, the end effector has a lot of dead angles when attempting to clamp the tissue. It is difficult to align the end effector with the tissue to be cut and stapled. At this time, another surgical instrument is required to enter the body cavity through another puncture needle to clamp the tissue to be cut and stapled between the staple anvil and the staple cartridge of the end effector. This requires an additional puncture needle on the human body on one hand, and adds a difficult surgery step on the other hand. Moreover, some tissue to be cut and stapled will be damaged when being pulled. Even if the tissue can be pulled, it is difficult to accurately clamp the tissue to be cut and stapled between the staple anvil and the staple cartridge of the end effector. Another disadvantage of such endoscopic surgical cutting stapler is that, when the radius of curvature of the bended slide bar is small, a radius of curvature of an inner thin plate of the slide bar is notably smaller than that of an outer thin plate. As a result, notable displacement is generated between the inner and the outer thin plates of the slide bar, and an acting force of the operating mechanism is concentrated on the inner thin plate, which significantly degrades the capability of the slide bar to pass the acting force of the operating mechanism onto the end effector, thereby affecting the capability of the end effector to clamp, fasten, cut, and staple the tissue. In addition, due to the small radius of curvature of the slide bar, the slide bar has a great resilience force, which not only increases the resistance during movement of the slide bar, but also affects placement after the joint rotation. Therefore, the articulation structure of the endoscopic surgical cutting stapler needs further improvement.
Apparently, different types of endoscopic surgical cutting staplers are designed in the prior art, and development of new endoscopic surgical cutting staplers is carried on to further improve endoscopic surgical cutting staplers massively used around the world every year, so that the end effector has a greater angle, is more accurate and more convenient in placement, and more efficient in use.